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<div class="moz-cite-prefix">On 2020-03-11 7:38 a.m., Christian
König wrote:<br>
</div>
<blockquote type="cite" cite="mid:85b1ab46-178d-1fcd-bd4a-e70696efa778@amd.com">
<div class="moz-cite-prefix">Am 11.03.20 um 12:30 schrieb Zhu,
James:<br>
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<blockquote type="cite" cite="mid:BYAPR12MB32851E367C4D553AABB13BB7E4FC0@BYAPR12MB3285.namprd12.prod.outlook.com">
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<p style="font-family:Arial;font-size:10pt;color:#0078D7;margin:15pt;" align="Left"> [AMD Official Use Only - Internal Distribution
Only]<br>
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<div style="font-family: Calibri, Arial, Helvetica,
sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"> ping<br>
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width:98%">
<div id="divRplyFwdMsg" dir="ltr"><font style="font-size:11pt" face="Calibri, sans-serif" color="#000000"><b>From:</b> Zhu, James <a class="moz-txt-link-rfc2396E" href="mailto:James.Zhu@amd.com" moz-do-not-send="true"><James.Zhu@amd.com></a><br>
<b>Sent:</b> Monday, March 9, 2020 12:57 PM<br>
<b>To:</b> <a class="moz-txt-link-abbreviated" href="mailto:amd-gfx@lists.freedesktop.org" moz-do-not-send="true">amd-gfx@lists.freedesktop.org</a>
<a class="moz-txt-link-rfc2396E" href="mailto:amd-gfx@lists.freedesktop.org" moz-do-not-send="true"><amd-gfx@lists.freedesktop.org></a><br>
<b>Cc:</b> Zhu, James <a class="moz-txt-link-rfc2396E" href="mailto:James.Zhu@amd.com" moz-do-not-send="true"><James.Zhu@amd.com></a>;
Koenig, Christian <a class="moz-txt-link-rfc2396E" href="mailto:Christian.Koenig@amd.com" moz-do-not-send="true"><Christian.Koenig@amd.com></a><br>
<b>Subject:</b> [PATCH v3 1/4] drm/amdgpu/vcn: fix
race condition issue for vcn start</font>
<div> </div>
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<div class="BodyFragment"><font size="2"><span style="font-size:11pt">
<div class="PlainText">Fix race condition issue
when multiple vcn starts are called.<br>
<br>
v2: Removed checking the return value of
cancel_delayed_work_sync()<br>
to prevent possible races here.<br>
<br>
v3: Add total_submission_cnt to avoid gate power
unexpectedly.<br>
<br>
Signed-off-by: James Zhu <a class="moz-txt-link-rfc2396E" href="mailto:James.Zhu@amd.com" moz-do-not-send="true"><James.Zhu@amd.com></a><br>
---<br>
drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.c | 22
+++++++++++++++-------<br>
drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.h | 2 ++<br>
2 files changed, 17 insertions(+), 7
deletions(-)<br>
<br>
diff --git
a/drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.c<br>
index a41272f..6aafda1 100644<br>
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.c<br>
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.c<br>
@@ -63,6 +63,8 @@ int amdgpu_vcn_sw_init(struct
amdgpu_device *adev)<br>
int i, r;<br>
<br>
INIT_DELAYED_WORK(&adev->vcn.idle_work,
amdgpu_vcn_idle_work_handler);<br>
+
mutex_init(&adev->vcn.vcn_pg_lock);<br>
+
atomic_set(&adev->vcn.total_submission_cnt,
0);<br>
<br>
switch (adev->asic_type) {<br>
case CHIP_RAVEN:<br>
@@ -210,6 +212,7 @@ int
amdgpu_vcn_sw_fini(struct amdgpu_device *adev)<br>
}<br>
<br>
release_firmware(adev->vcn.fw);<br>
+
mutex_destroy(&adev->vcn.vcn_pg_lock);<br>
<br>
return 0;<br>
}<br>
@@ -307,7 +310,8 @@ static void
amdgpu_vcn_idle_work_handler(struct work_struct
*work)<br>
fences += fence[j];<br>
}<br>
<br>
- if (fences == 0) {<br>
+ if (fences == 0 &&<br>
+
likely(atomic_read(&adev->vcn.total_submission_cnt)
== 0)) {<br>
amdgpu_gfx_off_ctrl(adev,
true);<br>
amdgpu_device_ip_set_powergating_state(adev,
AMD_IP_BLOCK_TYPE_VCN,<br>
AMD_PG_STATE_GATE);<br>
@@ -319,13 +323,14 @@ static void
amdgpu_vcn_idle_work_handler(struct work_struct
*work)<br>
void amdgpu_vcn_ring_begin_use(struct
amdgpu_ring *ring)<br>
{<br>
struct amdgpu_device *adev =
ring->adev;<br>
- bool set_clocks =
!cancel_delayed_work_sync(&adev->vcn.idle_work);<br>
<br>
- if (set_clocks) {<br>
- amdgpu_gfx_off_ctrl(adev,
false);<br>
-
amdgpu_device_ip_set_powergating_state(adev,
AMD_IP_BLOCK_TYPE_VCN,<br>
- AMD_PG_STATE_UNGATE);<br>
- }<br>
+
atomic_inc(&adev->vcn.total_submission_cnt);<br>
+
cancel_delayed_work_sync(&adev->vcn.idle_work);<br>
+<br>
+
mutex_lock(&adev->vcn.vcn_pg_lock);<br>
+ amdgpu_gfx_off_ctrl(adev, false);<br>
+
amdgpu_device_ip_set_powergating_state(adev,
AMD_IP_BLOCK_TYPE_VCN,<br>
+ AMD_PG_STATE_UNGATE);<br>
<br>
if (adev->pg_flags &
AMD_PG_SUPPORT_VCN_DPG) {<br>
struct dpg_pause_state
new_state;<br>
@@ -345,11 +350,14 @@ void
amdgpu_vcn_ring_begin_use(struct amdgpu_ring
*ring)<br>
<br>
adev->vcn.pause_dpg_mode(adev, ring->me,
&new_state);<br>
}<br>
+
mutex_unlock(&adev->vcn.vcn_pg_lock);<br>
}<br>
<br>
void amdgpu_vcn_ring_end_use(struct amdgpu_ring
*ring)<br>
{<br>
schedule_delayed_work(&ring->adev->vcn.idle_work,
VCN_IDLE_TIMEOUT);<br>
+ if
(unlikely(atomic_dec_return(&ring->adev->vcn.total_submission_cnt)
< 0))<br>
+
atomic_set(&ring->adev->vcn.total_submission_cnt,
0);<br>
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<br>
You need to decrement first and then call <font size="2"><span style="font-size:11pt">schedule_delayed_work() otherwise the
work could run with the wrong counter.<br>
<br>
And the extra check for an under run should be superfluous.<br>
</span></font></blockquote>
<p><font size="2">Thanks! Please check V4</font></p>
<p><font size="2">James<br>
</font></p>
<blockquote type="cite" cite="mid:85b1ab46-178d-1fcd-bd4a-e70696efa778@amd.com"><font size="2"><span style="font-size:11pt"> <br>
Regards,<br>
Christian.<br>
</span></font><br>
<blockquote type="cite" cite="mid:BYAPR12MB32851E367C4D553AABB13BB7E4FC0@BYAPR12MB3285.namprd12.prod.outlook.com">
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<div id="Signature">
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<div class="BodyFragment"><font size="2"><span style="font-size:11pt">
<div class="PlainText"> }<br>
<br>
int amdgpu_vcn_dec_ring_test_ring(struct
amdgpu_ring *ring)<br>
diff --git
a/drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.h
b/drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.h<br>
index 6fe0573..111c4cc 100644<br>
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.h<br>
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.h<br>
@@ -200,6 +200,8 @@ struct amdgpu_vcn {<br>
struct drm_gpu_scheduler
*vcn_dec_sched[AMDGPU_MAX_VCN_INSTANCES];<br>
uint32_t
num_vcn_enc_sched;<br>
uint32_t
num_vcn_dec_sched;<br>
+ struct mutex vcn_pg_lock;<br>
+ atomic_t
total_submission_cnt;<br>
<br>
unsigned harvest_config;<br>
int (*pause_dpg_mode)(struct
amdgpu_device *adev,<br>
-- <br>
2.7.4<br>
<br>
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